A single-chip 512-point FFT processor is presented. This processor is based on the cached-memory architecture (CMA) with the resource-saving multi-datapath radix-23 computation element. The 2-stage CMA, including a pair of single-port SRAMs, is also introduced to speedup the execution time of the 2-dimensional FFTs. Using the above techniques, we have designed an FFT processor core which integrates 552,000 transistors within an area of 2.82.8 mm2 with CMOS 0.35 µm triple-layer-metal process. This processor can execute a 512-point, 36-bit-complex fixed-point data format, 1-dimensonal FFT in 23.2 µsec and a 2-dimensional one in only 23.8 msec at 133 MHz operation. The power consumption of this processor is 439.6 mW at 3.3 V, 100 MHz operation.